474 JAPANESE LACQUER AND LACQUER WARE. 



The product thus purified is known as seshime urushi, but this name, 

 winch has already been used fco designate the lacquer from the branches, 

 has now a different meaning and is applied to the cheaper kinds of raw 

 lacquer, such asare used for the first coats in lacquering. These lacquers 

 have usually lost some of their water by stirring in shallow receptacles 

 exposed to the sun. They have undergone no further preparation. 



.Many varieties of lacquer are prepared for special purposes, ranging 

 in price from $1 or $2 to$G or $7 per kilogram. These differ in quality 

 and color. There is a famous black lacquer prepared by the addition 

 of iron which forms a chemical combination to be mentioned further 

 on; while red, green, yellow, and other colors are imparted by addi- 

 tion of various pigments, as cinnabar for red, orpimeut and indigo to- 

 gether for green, orpiment for yellow, etc. Ultramarine is decomposed • 

 by lacquer, giving off sulphuretted hydrogen. Certaiu lacquers have a 

 small proportion of a drying oil, ye no abura, perilla oil, added to them. 

 The lacquer kuownas shiu urushi, the useof which will be referred tosoou, 

 contains from 1 to 10 per cent, of this oil. The name shiu urushi means 

 cinnabar lacquer, and is applied to this variety because it is commouly 

 used to mix with cinnabar when a red lacquer is required. 



The chemical composition of lacquer has been well studied by Dr. J. 

 J. Rein,* and later by Korschelt and Yoshida. t From the writings of 

 these authors I have gathered most of the information here presented 

 relative to the chemistry of the subject. 



The emulsion as it comes from the tree consists of an aqueous fluid 

 holding in suspension numerous very minute brown globules and a 

 smaller proportion of lighter colored larger globules. The former are 

 insoluble in water but soluble in alcohol. The latter dissolve in water. 



The raw lacquer is almost completely soluble in alcohol, ether, carbon 

 bisulphide, benzine, and solvents of gum-resins iu general. The most, 

 important and abundant constituent is urushic acid, which occurs in the 

 form of the minute spherules already mentioned. The acid is obtained 

 by evaporatingthealcoholic solution toa sirupy liquid. The evaporation 

 must be carried on over a water-bath. If too much heat be applied a 

 tough, black, rubber-like substance is obtained, which I found very 

 troublesome to remove from the dish, and only strong nitric acid would 

 affect it in the slightest degree. 



As thus obtained, urushic acid yields on analysis numbers correspond- 

 ing approximately with the formula C 14 Hi 8 2 . This is the formula as- 

 signed to the acid by Korschelt and Yoshida. It is soluble in alcohol] 

 chloroform, etc., but quite insoluble in water. It possesses marked acid 

 properties, turns litmus paper red and forms salts with metals. With 

 iron salts it forms a black compound, to which the color of the flneroiro 



* Oesterreische Monatschrift fur den Orient 1882, and Japan nacli Reisen und Stu- 

 dien, vol. ii. 



t Trans. Asiatic >Soc. of Japan, xii (1884) 182-229. Also Forestry and Forest Prod- 

 ucts. Edinburgh, 1885. 





